Separating changes in the intra- and extracellular water apparent diffusion coefficient following focal cerebral ischemia in the rat brain
Department of Neurology; Department of Radiology; Graduate School of Biomedical Sciences
Animals; Brain Ischemia; Diffusion Magnetic Resonance Imaging; Extracellular Space; Intracellular Fluid; Male; Rats; Rats, Sprague-Dawley; Spectrum Analysis; Water
Neurology | Neuroscience and Neurobiology
Selective intracellular (IC) and extracellular (EC) brain water apparent diffusion coefficient (ADC) values were measured in normal and ischemic rat brain. Selective T(1)-relaxation enhancement of the EC water, using intracerebroventricular (ICV) infusion of an NMR contrast reagent (CR), was used to separate the IC and EC signal contributions. In the CR-infused, normal brain (n = 4), T(1) = 235 +/- 10 ms and T(2) = 46 +/- 2 ms for IC water (85%) and T(1) = 48 +/- 8 ms and T(2) = 6 +/- 2 ms for EC water (15%). Volume-localized ADC(z) (z-gradient axis) values were 0.90 +/- 0.02 (EC+IC), 0.81 +/- 0.05 (IC), 0.51 +/- 0.02 (EC+IC), and 0.53 +/- 0.07 (IC), for normal, CR-infused, ischemic, and ischemic/CR-infused groups, respectively (ADC values are x10(-3) mm(2)/s; n = 5 for each group). Imaging ADC(z) values were 0.81 +/- 0.03 (EC+IC), 0.75 +/- 0.05 (IC), 0.51 +/- 0.04 (EC+IC), and 0.52 +/- 0.05 (IC), respectively, for the same groups. Imaging ADC(av) (average diffusivity) values for the same groups were 0.70 +/- 0.05 (EC+IC), 0.69 +/- 0.06 (IC), 0.45 +/- 0.06 (EC+IC), and 0.44 +/- 0.06 (IC), respectively. These results suggest that the IC water ADC determines the overall water ADC value in normal and ischemic rat brain.
DOI of Published Version
Magn Reson Med. 2002 Nov;48(5):826-37. Link to article on publisher's site
Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine
Silva, Matthew D.; Omae, Tsuyoshi; Helmer, Karl G.; Li, Fuhai; Fisher, Marc; and Sotak, Christopher H., "Separating changes in the intra- and extracellular water apparent diffusion coefficient following focal cerebral ischemia in the rat brain" (2002). Neurology Publications and Presentations. 95.